The study failed to mention two researchers' links to abortion rights. Some ethicists call the omission regrettable.

CHICAGO — A controversial research article about when fetuses feel pain is sparking a heated debate about the nexus between science and politics and what information authors should disclose to scientific journals.

The report, published Wednesday in the Journal of the American Medical Assn., analyzed previously published research and concluded that fetuses probably don't feel pain until 29 weeks after conception because of their developing brain structures.

Undisclosed was the fact that one of the five authors runs an abortion clinic at San Francisco's public hospital while another author worked temporarily more than five years ago for an abortion rights advocacy group.

Several ethicists said they considered those points regrettable omissions that left readers without important information. Other experts consider the authors' backgrounds irrelevant.

"The standard for disclosure in medical and scientific journals is not your politics. There's no obligation to tell people what your mind-set is ... as long as the data is sound and gathered objectively," said Dr. Alan Leff, a University of Chicago pulmonologist and editor of the Proceedings of the American Thoracic Society.

Antiabortion groups insist that the authors' affiliations are crucially important.

"These are people with years of professional and ideological investment in the pro-abortion cause, not some neutral team of medical professionals," said Douglas Johnson, legislative director of the National Right to Life Committee. "We think readers and viewers have a right to know who's filtering the information they're being presented with."

The two researchers in question are Dr. Eleanor A. Drey, an associate clinical professor in the department of obstetrics and gynecology at UC San Francisco, and Susan J. Lee, a medical student. Their colleagues included a neuro-anatomist, an anesthesiologist and a pediatrician.

Drey runs an abortion clinic at San Francisco General Hospital. Lee spent eight months working as a lawyer for the National Abortions Rights Action League in 1999 and 2000 before going to medical school. Neither affiliation was disclosed to JAMA's editors or to readers.

Dr. Philip Darney, chief of obstetrics, gynecology and reproductive sciences at San Francisco General Hospital, defended that decision, saying in a statement: "The research team does not believe that being an abortion provider is a conflict of interest."

Medical journals require authors to disclose financial ties to industry or other funding sources. But there are no standards for disclosing other factors that might influence an author, such as clinical practices or organizational affiliations.

Dr. Catherine DeAngelis, JAMA's editor in chief, said she wasn't concerned by Drey's failure to indicate she performed abortions.

"That's part of [an ob-gyn's] scope of practice. They don't have to reveal that."

As for Lee, DeAngelis said: "Was she a college student [when she worked for NARAL]? Is she a member? I don't know. I'm going to find out ... [and] I want the authors to have the opportunity to explain why they didn't reveal it."

A Roman Catholic who opposes abortion, DeAngelis said she had been swamped over the last several days with critical e-mails about the fetal pain study from "people with no medical background, no science background, religious fanatics, people who are mean-spirited."

She stressed that the report was reviewed by several outside experts and thoroughly vetted by her staff.

"It is a peer-reviewed article," DeAngelis said. "They are not reporting their own findings."